React Native Quickstart

Learn how to query data from Convex in a React Native app.

1. Create a React Native app

   Create a React Native app using the npx create-expo-app command.

   npx create-expo-app my-app
2. Install the Convex client and server library

   To get started, install the convex package which provides a convenient interface for working with Convex from a React app.

   Navigate to your app and install convex.

   cd my-app && npm install convex
3. Set up a Convex dev deployment

   Next, run npx convex dev. This will prompt you to log in with GitHub, create a project, and save your production and deployment URLs.

   It will also create a convex/ folder for you to write your backend API functions in. The dev command will then continue running to sync your functions with your dev deployment in the cloud.

   npx convex dev
4. Create sample data for your database

   Create a sampleData.jsonl file with some sample data.

   sampleData.jsonl

   {"text": "Buy groceries", "isCompleted": true}
   {"text": "Go for a swim", "isCompleted": true}
   {"text": "Integrate Convex", "isCompleted": false}
5. Add the sample data to your database

   Now that your project is ready, add a tasks table with the sample data into your Convex database with the import command.

   npx convex import --table tasks sampleData.jsonl
6. Expose a database query

   Add a new file tasks.ts in the convex/ folder with a query function that loads the data.

   Exporting a query function from this file declares an API function named after the file and the export name, api.tasks.get.

   convex/tasks.ts

   import { query } from "./_generated/server";
   
   export const get = query({
     args: {},
     handler: async (ctx) => {
       return await ctx.db.query("tasks").collect();
     },
   });
7. Reset the Expo project

   If you haven't done so yet, reset the Expo project to get a fresh app directory.

   npm run reset-project
8. Connect the app to your backend

   In _layout.tsx, create a ConvexReactClient and pass it to a ConvexProvider wrapping your component tree.

   app/_layout.tsx

   import { ConvexProvider, ConvexReactClient } from "convex/react";
   import { Stack } from "expo-router";
   
   const convex = new ConvexReactClient(process.env.EXPO_PUBLIC_CONVEX_URL!, {
     unsavedChangesWarning: false,
   });
   
   export default function RootLayout() {
     return (
       <ConvexProvider client={convex}>
         <Stack>
           <Stack.Screen name="index" />
         </Stack>
       </ConvexProvider>
     );
   }
9. Display the data in your app

   In index.tsx use the useQuery hook to fetch from your api.tasks.get API.

   app/index.tsx

   import { api } from "@/convex/_generated/api";
   import { useQuery } from "convex/react";
   import { Text, View } from "react-native";
   
   export default function Index() {
     const tasks = useQuery(api.tasks.get);
     return (
       <View
         style={{
           flex: 1,
           justifyContent: "center",
           alignItems: "center",
         }}
       >
         {tasks?.map(({ _id, text }) => <Text key={_id}>{text}</Text>)}
       </View>
     );
   }
10. Start the app

    Start the app, scan the provided QR code with your phone, and see the serialized list of tasks in the center of the screen.

    npm start

React native uses the same library as React web. See the complete React documentation.